There is already known from patent document CH 650 894 a watch which exhibits a caseband provided with an annular shoulder and a crystal on which is provided an annular clamping surface. This assembly has been conceived in a manner such that when one secures the crystal to the case, a portion of the annular surface of the crystal comes to rest on the periphery of the dial which has been initially centered by a notch provided on its edge in order to immobilize the latter against the annular shoulder.
If these means provide an advantage in connecting the caseband and the crystal while positioning the dial, there nevertheless remains the fact that the movement must be maintained in all circumstances correctly positioned within the case, and such has not been suggested within this document.
Effectively, in the case of watches of the chronograph type having push-buttons, the push-button or push-buttons when actuated exert forces on the order of a kilogramme on the movement. Such forces tend then to bring about a lateral displacement of the movement in the case which, in the absence of lateral positioning means will, following a certain period of time, cause play in the positioning of the movement in the case which is detrimental to proper functioning of the chronograph. This phenomenon is accentuated in instances where the case is formed of a soft material such as plastic material.
Furthermore, the absence of such lateral positioning during the assembly of the movement in the case, because of the poor centering of the axis of the hands relative to the dial, risks distorting reading of the time and consequently spoiling the aesthetic aspect of the watch.
The invention thus has as its principal purpose to overcome these difficulties of the prior art as mentioned hereinabove in providing a watch in which the movement is laterally positioned in a simple and certain fashion within the watch case.